8 ALASKAN GLACIER STUDIES The Harriman Alaska Expedition visited Glacier Bay in 1899 and John Muir and G. K. Gilbert studied the glaciers and glaciation.1 Andrews and Casea made brief observations of Muir Glacier in 1902, and a United States Geological Survey Expedition in 1906, under charge of F. E. and C. W. Wright, made detailed studies and maps, as yet only published in abstract.8 In 1907 the Boundary Survey work resulted in additional observations which have been briefly described by Klotz 4 and by Morse6 and more recently published in a new United States Coast and Geodetic Survey chart8 whose comparison with that of 1892 7 shows the great glacial retreat that has been going on in this region and which has been summarized by H. F. Reid.8 In 1911 Glacier Bay was visited by the authors of t.Tiia book9 who found most of the ice tongues retreating, though Rendu Glacier had advanced l£ miles. In 1912 the Grand Pacific Glacier was mapped by N. J. Ogilvie of the Canadian Boundary Survey, who found that it retreated 1£ miles during two months, making a new Canadian harbor.10 In 1918 Glacier Bay was visited by an excursion of the International Geological Congress.11 Afterwards the junior author of this book studied several of the ice tongues of Glacier Bay, finding that Grand Pacific Glacier had readvanced and destroyed the new Canadian harbor,12 and that the Reid, Lamplugh, and de Margerie Glaciers had also advanced. A great number of popular descriptions of Muir and other Glacier Bay ice tongues have been written.18 Davidson has summarized the information based upon the maps and reports of Vancouver, Tebenkof, and the Russian navigators and agrees with Wright and Reid that Muir Glacier and the other ice tongues of Glacier Bay extended 25 to 40 miles farther to the south in 1794. He also refers to native legends of the greater extension of these glaciers.14 Muir Glacier receded about 1$ miles between Muir's observations of 1879-1880 and Reid's in 1890 and the several fronts of Grand Pacific Glacier retreated from one to six miles. Between 1890 and 1892 Muir Glacier advanced about 800 yards, retreating about the same amount between 1892 and 1894. Between 1879 and 1896 Rendu and Carroll Glaciers retreated 2 to 4 miles. Between 1899 and 1907 Muir Glacier retreated about 8| miles and Grand Pacific Glacier about 8 miles. The rapid retreat of the » Harriman Alaska Expedition, Vol. ffl, 1004, pp. 16-39. »Nat. Geog. Mag., Vol. XIV, 1903, pp. 441-444. »Jouin. Geol., Vol. XVI, 1908, pp. 62-53. • Klotz, Otto, Geog. Journ,, Vol. XXX, 1907, pp. 419-421. • Morse, Fremont, Nat. Geog. Mag., Vol. XIX, 1908, pp. 76-78. • Chart 8306. r Chart 8095. • Variations of Glaciers, Journ. Geol., Vol. IX, 1901, p. 253; X, 1902, p. 317; XI, 1903, p. 287; XH. 1904, pp. 258-260. • See H. F. Reid's Variations of Glaciers, Journ. Geol., Vol. *"KT, 1918, pp. 425-426. "Martin, Lawrence, Glaciers and International Boundaries, Scientific American Supplement, Vol. LXXVI, 1913, pp. 129, 186-138. "Martin, Lawrence, Guide Book No. 10, Excursion,C 8, International Geological Congress, Ottawa, 1913, pp. 121-182, and table of errata. « Martin, Lawrence, The Literary Digest, Vol. XLVH, No. 1229, Nov. 8. 1913, p. 871, and thiee maps. 11 Burroughs, John, Harriman Alaska Expedition, Vol. 1,1902, pp. 85-48. Egerton, H. G., Alaska and Its Glaciers, Nineteenth Century, Vol. 22, pp. 997-999. " Davidson, George, Trans, and Proc. Geog. Soc. Pacific, VoL, HE, 1904, pp. 66-72.